#include <iostream>
#include<set>

using namespace std;


int a[] = {10, 60, 20, 70, 80, 30, 90, 40, 100, 50};
int main()
{
	set<int> mp;
	for(auto& x : a)
	{
		mp.insert(x);
	}
	for(auto& x : mp)
	{
		cout << x << " ";
	}
	cout << endl;
	if(mp.count(1)) 
	    cout << "1" << endl;
	else
	    cout << "no" << endl;
	mp.erase(60);
	for(auto& x : mp)
	{
		cout << x << " ";
	}
	cout << endl;
	auto x = mp.lower_bound(30);
	auto y = mp.upper_bound(30);
	cout << *x << " " << *y << endl;
	return 0;
}
